In many military and law enforcement situations, it is desirable to perform control, surveillance and reconnaissance, communication, and other tasks without exposing personnel to dangerous situations.
For example, it is often necessary for military and law enforcement personnel to enter buildings and other enclosed structures and spaces. Entry into structures is done for various reasons, including searching the interiors of the structures, surveillance and reconnaissance, and apprehending individuals within the structures.
For military and law enforcements personnel, entry into structures can be extremely dangerous. Often, the personnel may not know whether there are potentially dangerous or potentially friendly occupants within a structure, how many occupants there are, or where the occupants are located within the structure. In addition, the personnel may not know the interior configuration of the structure or the location of potentially dangerous obstacles. As a result of these unknowns, the personnel may need to make spur of the moment decisions during and after entry, which can lead to dangerous, and potentially fatal, errors in judgment. Further, to enter a structure, the personnel often leave the safe confines of a location, for example an armored vehicle, thereby exposing themselves to potential danger prior to entry.
The use of unmanned vehicles for performing control, surveillance, reconnaissance, communications, and other tasks is known. These include ground based remote-controlled wheeled or tracked vehicles, and aerial vehicles including the Honeywell Micro Air Vehicle, the Honeywell Kestrel, and the Allied Aerospace iSTAR.
Many prior unmanned vehicles are powered by combustion engines, making the vehicles noisy even with sounds mufflers in place. In addition, the use of an engine(s) and the need to carry the requisite fuel supply increases the weight of the vehicle, thereby decreasing the portability of the vehicle, especially by humans.